Add limit and offset parse error

Author: zaneli

dialect.go

@@ -37,7 +37,7 @@ type Dialect interface {
 	ModifyColumn(tableName string, columnName string, typ string) error
 
 	// LimitAndOffsetSQL return generated SQL with Limit and Offset, as mssql has special case
-	LimitAndOffsetSQL(limit, offset interface{}) string
+	LimitAndOffsetSQL(limit, offset interface{}) (string, error)
 	// SelectFromDummyTable return select values, for most dbs, `SELECT values` just works, mysql needs `SELECT value FROM DUAL`
 	SelectFromDummyTable() string
 	// LastInsertIDOutputInterstitial most dbs support LastInsertId, but mssql needs to use `OUTPUT`

dialect_common.go

@@ -139,14 +139,23 @@ func (s commonDialect) CurrentDatabase() (name string) {
 	return
 }
 
-func (commonDialect) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
+// LimitAndOffsetSQL return generated SQL with Limit and Offset
+func (s commonDialect) LimitAndOffsetSQL(limit, offset interface{}) (sql string, err error) {
 	if limit != nil {
-		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
+		parsedLimit, err := s.parseInt(limit)
+		if err != nil {
+			return "", err
+		}
+		if parsedLimit >= 0 {
 			sql += fmt.Sprintf(" LIMIT %d", parsedLimit)
 		}
 	}
 	if offset != nil {
-		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
+		parsedOffset, err := s.parseInt(offset)
+		if err != nil {
+			return "", err
+		}
+		if parsedOffset >= 0 {
 			sql += fmt.Sprintf(" OFFSET %d", parsedOffset)
 		}
 	}
@@ -181,6 +190,10 @@ func (commonDialect) NormalizeIndexAndColumn(indexName, columnName string) (stri
 	return indexName, columnName
 }
 
+func (commonDialect) parseInt(value interface{}) (int64, error) {
+	return strconv.ParseInt(fmt.Sprint(value), 0, 0)
+}
+
 // IsByteArrayOrSlice returns true of the reflected value is an array or slice
 func IsByteArrayOrSlice(value reflect.Value) bool {
 	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))

dialect_mysql.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"reflect"
 	"regexp"
-	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -140,13 +139,21 @@ func (s mysql) ModifyColumn(tableName string, columnName string, typ string) err
 	return err
 }
 
-func (s mysql) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
+func (s mysql) LimitAndOffsetSQL(limit, offset interface{}) (sql string, err error) {
 	if limit != nil {
-		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
+		parsedLimit, err := s.parseInt(limit)
+		if err != nil {
+			return "", err
+		}
+		if parsedLimit >= 0 {
 			sql += fmt.Sprintf(" LIMIT %d", parsedLimit)
 
 			if offset != nil {
-				if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
+				parsedOffset, err := s.parseInt(offset)
+				if err != nil {
+					return "", err
+				}
+				if parsedOffset >= 0 {
 					sql += fmt.Sprintf(" OFFSET %d", parsedOffset)
 				}
 			}

dialects/mssql/mssql.go

@@ -168,14 +168,25 @@ func (s mssql) CurrentDatabase() (name string) {
 	return
 }
 
-func (mssql) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
+func (mssql) LimitAndOffsetSQL(limit, offset interface{}) (sql string, err error) {
+	parseInt := func(value interface{}) (int64, error) {
+		return strconv.ParseInt(fmt.Sprint(value), 0, 0)
+	}
 	if offset != nil {
-		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
+		parsedOffset, err := parseInt(offset)
+		if err != nil {
+			return "", err
+		}
+		if parsedOffset >= 0 {
 			sql += fmt.Sprintf(" OFFSET %d ROWS", parsedOffset)
 		}
 	}
 	if limit != nil {
-		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
+		parsedLimit, err := parseInt(limit)
+		if err != nil {
+			return "", err
+		}
+		if parsedLimit >= 0 {
 			if sql == "" {
 				// add default zero offset
 				sql += " OFFSET 0 ROWS"

query_test.go

@@ -457,6 +457,74 @@ func TestOffset(t *testing.T) {
 	}
 }
 
+func TestLimitAndOffsetSQL(t *testing.T) {
+	user1 := User{Name: "TestLimitAndOffsetSQL1", Age: 10}
+	user2 := User{Name: "TestLimitAndOffsetSQL2", Age: 20}
+	user3 := User{Name: "TestLimitAndOffsetSQL3", Age: 30}
+	user4 := User{Name: "TestLimitAndOffsetSQL4", Age: 40}
+	user5 := User{Name: "TestLimitAndOffsetSQL5", Age: 50}
+	if err := DB.Save(&user1).Save(&user2).Save(&user3).Save(&user4).Save(&user5).Error; err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		name          string
+		limit, offset interface{}
+		users         []*User
+		ok            bool
+	}{
+		{
+			name:   "OK",
+			limit:  float64(2),
+			offset: float64(2),
+			users: []*User{
+				&User{Name: "TestLimitAndOffsetSQL3", Age: 30},
+				&User{Name: "TestLimitAndOffsetSQL2", Age: 20},
+			},
+			ok: true,
+		},
+		{
+			name:   "Limit parse error",
+			limit:  float64(1000000), // 1e+06
+			offset: float64(2),
+			ok:     false,
+		},
+		{
+			name:   "Offset parse error",
+			limit:  float64(2),
+			offset: float64(1000000), // 1e+06
+			ok:     false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var users []*User
+			err := DB.Where("name LIKE ?", "TestLimitAndOffsetSQL%").Order("age desc").Limit(tt.limit).Offset(tt.offset).Find(&users).Error
+			if tt.ok {
+				if err != nil {
+					t.Errorf("error expected nil, but got %v", err)
+				}
+				if len(users) != len(tt.users) {
+					t.Errorf("users length expected %d, but got %d", len(tt.users), len(users))
+				}
+				for i := range tt.users {
+					if users[i].Name != tt.users[i].Name {
+						t.Errorf("users[%d] name expected %s, but got %s", i, tt.users[i].Name, users[i].Name)
+					}
+					if users[i].Age != tt.users[i].Age {
+						t.Errorf("users[%d] age expected %d, but got %d", i, tt.users[i].Age, users[i].Age)
+					}
+				}
+			} else {
+				if err == nil {
+					t.Error("error expected not nil, but got nil")
+				}
+			}
+		})
+	}
+}
+
 func TestOr(t *testing.T) {
 	user1 := User{Name: "OrUser1", Age: 1}
 	user2 := User{Name: "OrUser2", Age: 10}

scope.go

@@ -797,7 +797,9 @@ func (scope *Scope) orderSQL() string {
 }
 
 func (scope *Scope) limitAndOffsetSQL() string {
-	return scope.Dialect().LimitAndOffsetSQL(scope.Search.limit, scope.Search.offset)
+	sql, err := scope.Dialect().LimitAndOffsetSQL(scope.Search.limit, scope.Search.offset)
+	scope.Err(err)
+	return sql
 }
 
 func (scope *Scope) groupSQL() string {